From: DL4YHF@aol.com
Message-ID: <54.1523ede1.2843db49@aol.com>
Date: Mon, 28 May 2001 12:48:09 EDT
Subject: LF: GBR Info - Thanks !
To: rsgb_lf_group@blacksheep.org
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<HTML><FONT FACE=arial,helvetica><FONT  SIZE=2>Hi Alan, Andy, John &nbsp;and the group,
<BR>
<BR>Thanks for the quick response to my question about the 16kHz-signal.
<BR>
<BR>I must have missed the information formerly posted about MSK on 16kHz on this 
<BR>reflector, but now I got the picture ;-). As the signal is MSK, it is a 
<BR>special kind of FSK (modulation index 0.5) but also a special kind of PSK, 
<BR>and it once was RTTY some time ago.
<BR>
<BR>Also ok on the 'temporary mode switch' from MSK to CW on Tuesday afternoon. 
<BR>For those who don't have the posting, here it comes again (originally relayed 
<BR>by G3XDV from G4KHU):
<BR>&gt; "Listeners may be aware that the UK Royal Navy are celebrating the
<BR>&gt; Centenary of the Royal Navy Submarine service with a gathering of UK and
<BR>&gt; overseas submarines in the Clyde. This year is also the 75th anniversary
<BR>&gt; of operation of the GBR transmitter (Rugby). 
<BR>&gt; As part of this celebration 'It is hoped' that a special A1A Morse code
<BR>&gt; transmission from the GBR long wave transmitter will be made.
<BR>&gt; For those with an interest in VLF reception please listen to 16kHz (yes 16
<BR>&gt; not 60kHz!) on Tuesday 29th May 2001 at 1200GMT and 1345GMT."
<BR>
<BR>--
<BR>
<BR>To John G4CNN, asking about PC-based reception below 10kHz:
<BR>
<BR>Hmm.. well.. the system does receive below 10kHz but I don't know how good. I 
<BR>don't have a commercial receiver which goes below 10kHz, so I cannot compare 
<BR>my RX system to &nbsp;a professional RX. I don't even know a (reliable) signal 
<BR>between 1 and 10kHz to listen for. The RX antenna is a heavy bundle of 19 
<BR>ferrite rods, insulated from each other to avoid currents in the 
<BR>semiconducting material, and 400 turns of wire. Total inductivity about 30 
<BR>millihenry, parallel caps for resonance between 15..20kHz and a high-current 
<BR>JFET as impedance converter (no voltage gain required for the MIC input of 
<BR>the PC). With more C's shunted it will work on even lower frequencies, but 
<BR>not very good I suppose.
<BR>
<BR>
<BR>73, Wolf, DL4YHF.
<BR></FONT></HTML>